1. Field of the Invention
The present invention generally relates to an endoscope apparatus, and more particularly, to a colonoscope apparatus.
2. Description of the Related Art
An endoscope apparatus may be used to screen, that is, capture and examine, the interior of a large intestine to discover lesions in the large intestine.
FIG. 1 is a diagram describing screening of the interior of a large intestine by using a general endoscope apparatus 10. Referring to FIG. 1, the endoscope apparatus 10 includes a front-view optical system capable of imaging an object in front of the endoscope, and a field-of-view 11 of the front-view optical system is limited to the front of the endoscope. An observer moves the endoscope apparatus 10 backward to screen an interior 21 of a large intestine 20.
As illustrated in FIG. 1, if a lesion 30 is occluded by a curved portion 22 of the large intestine, the lesion 30 is out of the field-of-view 11 of the endoscope apparatus 10, and thus fails to be detected.
When existence of a lesion is determined merely with a front-view or front-view-observation optical system, it is not easy to detect a lesion occluded by a curved portion of a large intestine. Moreover, to observe the lesion occluded by the curved portion and observe the lesion in detail within the field of view of the endoscope apparatus, a front end portion of the endoscope apparatus may be often bent.
Therefore, a need exists for an endoscope apparatus capable of easily detecting a lesion, making it easy to observe in detail a lesion without bending of the endoscope apparatus, and minimizing a diameter of a front end portion of the endoscope apparatus.